Genes encoding protein participating in cytokinin synthesis

ABSTRACT

A gene is provided that encodes an amino acid sequence indicated in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14 originating in, for example,  Arabidopsis thaliana.

FIELD OF THE INVENTION

[0001] The present invention relates to a gene encoding a protein involved in cytokinin synthesis, a method of utilizing that gene, and a method for acquiring that gene.

BACKGROUND ART

[0002] Cytokinins are an important type of plant hormone. They have various effects including induction of cell division, formation of new buds, overcoming dormancy of axillary buds, prevention of aging and promotion of enlargement of fruit. Cytokinins have a structure in which a dimethylallyl group (isopentenyl group) bonds to a nitrogen atom at position 6 of adenine or adenosine, or has a structure in which the isopentenyl group is hydroxylated as their basic skeleton. Some bacteria that are pathogenic to plants are known to have cytokinin synthesis enzymes and among these, the cytokinin synthases of IPT and TZS of Agrobacterium are known to have activity that transfers the dimethylallyl group of dimethylallyl pyrophosphoric acid (DMAPP) to the nitrogen atom at position 6 of adenosine monophosphate (AMP). This reaction is considered to be the most important step in cytokinin synthesis. However, cytokinin synthesis enzymes possessed by plants and the proteins that encode them have yet to be identified.

DISCLOSURE OF THE INVENTION

[0003] Therefore, an object of the present invention is to provide a gene that encodes an enzyme that catalyzes cytokinin synthesis, a protein encoded thereby, and its application. In addition, an object of the present invention is to provide a method for identifying that gene.

[0004] The inventors of the present invention found a method for obtaining a novel gene that encodes an enzyme that catalyzes cytokinin synthesis from Arabidopsis thaliana, and obtained a novel gene that encodes an enzyme that catalyzes cytokinin synthesis.

[0005] Thus, the present invention provides a gene that encodes a protein involved in cytokinin synthesis. More specifically, the protein is a previously unreported enzyme in plants that catalyzes the reaction in which a side chain is introduced at position N6 of the adenine skeleton of cytokinins.

[0006] More specifically, the present invention provides a gene that encodes a protein involved in cytokinin synthesis having the amino acid sequence described in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14. In addition, the present invention provides a gene that encodes a protein involved in cytokinin synthesis having a modified amino acid sequence resulting from the addition and/or deletion of one or a plurality of amino acids and/or substitution by other amino acids in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14. Moreover, the present invention provides a gene encoding a protein involved in cytokinin synthesis that hybridizes with a nucleic acid described in SEQ ID NO. 1, 3, 5, 7, 9, 11 or 13, and particularly DNA or a portion thereof, under stringent conditions.

[0007] The present invention also provides a vector that contains that gene.

[0008] Moreover, the present invention provides a host that has been transformed by that vector. This host may be a plant cell or a plant body.

[0009] The present invention is also able to provide a production method of a protein involved in cytokinin synthesis by culturing and cultivating the aforementioned host.

[0010] In addition, the present invention is able to provide a method for regulating the growth of a plant or plant cells by introducing the aforementioned gene into a plant or plant cells and expressing said gene. Namely, various physiological actions in which cytokinins are involved, such as promotion of the formation of adventitious buds, overcoming the dormancy of lateral buds, prevention of the aging of flowers and leaves and the ripening of fruit, improving the longevity of flowers, maintaining photosynthesis function, promoting the enlargement of fruit, prevention of dropping and control of flowering, can be regulated by expressing this gene.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a drawing showing the structure of plasmid pTK015.

[0012]FIG. 2 is a photograph of a plant body regenerated from Arabidopsis thaliana transformed by pHM4-AtIPT5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The inventors of the present invention surmised that the reaction that catalyzes the introduction of an isopentenyl (dimethylallyl) side chain at the N6 position of the adenine skeleton is the rate-limiting step of cytokinin synthesis. Examples of genes that are known to encode isopentenyl group transferases involved in cytokinin synthesis include the idt (gene4) gene encoded by T-DNA and the tzs gene present in the vir region of the Ti-plasmid of Agrobacterium tumefaciens, the Dtz gene present in several species of Pseudomonas, the ipt gene of Rhodococcus faciens, and the etz gene of Erwinia herbicola. Among these, the gene products of the tzs and ipt genes of Agrobacterium, the etz gene of Pseudomonas and the ipt gene of Rhodococcus have been demonstrated to have DMAPP:AMP dimethylallyl transferase activity in vitro. In addition to these, many living organisms have enzymes that transfer an isopentenyl group from DMAPP to rRNA. If plant cytokinins are assumed to be synthesized by isopentenylation of the adenine skeleton, then there is the possibility that enzymes that catalyze this reaction may have amino acids in common with the isopentenyl group transferases mentioned above. Therefore, the amino acid sequences of these gene products were first compared to find the amino acid residues preserved therein. The resulting sequence was determined to be GxTxxGK[ST]xxxxx[VLI]xxxxxxx[VLI] [VLI] xxDxxQx[57,60][VLI][VLI]xGG[ST]. Here, x indicates an arbitrary amino acid, amino acid residues enclosed in brackets [ ] indicate which one of the amino acid residues contained therein, and [a,b] indicates the number of arbitrary types of amino acid residues greater than or equal to a but less than or equal to b.

[0014] The genome sequence of Arabidopsis thaliana was searched using a TAIR Pattern Matching program to find the possible genes or estimated gene regions based on this amino acid sequence pattern. The resulting eight genes consisted of AT4g24650 (number of the estimated gene region as determined by the Genome Project), T20010_(—)210 (number of the estimated gene region as determined by the Genome Project), 29375-30301 bp of T16G12 (accession number: AC068809) genome clone, MDB19.12 (number of the estimated gene region as determined by the Genome Project), MVI11.6 (number of the estimated gene region as determined by the Genome Project), T26J14.3 (number of the estimated gene region as determined by the Genome Project), F2J7.12 (number of the estimated gene region as determined by the Genome Project) and AF109376.

[0015] Among these eight genes, an estimated gene, AF109376, has been cloned as the cDNA and annotated as being tRNA isopentenyl transferase mRNA. Among the seven remaining genes, T20010_(—)210, MDB19.12, AT4g24650, MVI11.6, T26J14.3 and F2J7.12 have not being isolated as full length cDNA but estimated genes, and annotated to be likely tRNA isopentenyl transferases. 29375-30301 bp of T16G12 (accession number: AC0699089) genome clone is not even annotated.

[0016] The genes or estimated genes of AT4g24650, T20010_(—)210, cDNA corresponding to 29375-30301 bp of T16G12 (accession number: AC068809) genome clone, MDB19.12, MVI11.6, T26J14.3 and F2J7.12 are designated AtIPT4, AtIPT3, AtIPT5, AtIPT7, AtIPT8 and AtIPT6. In addition, each of their nucleotide sequences are shown with SEQ ID NOs. 1, 3, 5, 7, 9, 11 and 13, and their corresponding amino acid sequences are indicated with SEQ ID NOs. 2, 4, 6, 8, 10, 12 and 14.

[0017] Although the calli of Arabidopsis thaliana normally form leaves and buds (to be referred to as shoots) when cytokinins are present in the medium, if cytokinins are not present, it does not form any shoots or even if they are formed, the frequency of formation is extremely low. Therefore, if callus efficiently forms shoots even in the absence of cytokinins when a gene has been introduced and expressed in the callus, the introduced gene can be considered to encode a cytokinin synthase or protein involved in cytokinin reactions.

[0018] Alternatively, by expressing the resulting gene using a gene expression system such as E. coli or yeast and then measuring the enzyme activity, the resulting gene can be confirmed to encode a cytokinin synthase or protein involved in cytokinin reactions.

[0019] On the basis of the above, in the present invention, a gene that encodes a cytokinin synthase or protein involved in cytokinin synthesis of plant origin was isolated and identified for the first time.

[0020] In addition, in the present invention, plant cytokinin synthase was found to transfer the DMA group of DMAPP to ATP and ADP.

[0021] Examples of a gene of the present invention include that coding for the amino acid sequence described in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14. However, proteins having an amino acid sequence that has been modified by addition or deletion or a plurality of amino acids, and/or substitution by other amino acids are known to maintain activity similar to the original protein. Thus, a modified gene that encodes a cytokinin synthase or protein involved in cytokinin synthesis activity and has an amino acid sequence that has been modified with respect to an amino acid sequence described in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14 by addition or deletion of one or a plurality of amino acids and/or substitution by other amino acids, is also included in the present invention.

[0022] Here, the degree of this modification is the degree which is possible by means that were commonly known technologies prior to filing of the present patent application, examples of which include site-specific mutagenesis, PCR method and so on. The number of amino acids subject to modification while maintaining the activity of the cytokinin synthase or that relating to cytokinin synthesis is, for example 100 or less, for example 50 or less, preferably 25 or less, and for example 10 or less.

[0023] In addition, the present invention also provides a gene composed of DNA that encodes a cytokinin synthase or protein having activity involved in cytokinin synthesis, and which is capable of hybridizing with a nucleic acid having a nucleotide sequence described in SEQ ID NO. 1, 3, 5, 7, 9, 11 or 13, or portion thereof, under stringent conditions. Here, stringent conditions refer to hybridization conditions consisting of 5×SSC and 50° C. Furthermore, as the suitable hybridization temperature varies according to the particular nucleotide sequence and the length of that nucleotide sequence, hybridization can be carried out by suitable selecting the hybridization temperature.

[0024] A cDNA library, genomic DNA library and so forth prepared from a plant or microorganism, etc. having cytokinin synthase activity or activity involved in cytokinin synthesis can be used for the source of the gene subjected to the aforementioned hybridization, examples of which include plants such as Arabidopsis thaliana, corn, poplar, petunia, tobacco, rice, tomato and eucalyptus plants.

[0025] The nucleotide sequence of a gene encoding a cytokinin synthase or protein involved in cytokinin synthesis obtained in this manner has homology of 50% or more, 60% or more, preferably 70% or more or 80% or more, and for example 90% or more, with respect to a nucleotide sequence indicated in SEQ ID NO. 1, 3, 5, 7, 9, 11 or 13.

[0026] As will be concretely indicated in the examples, the subject gene encoding a protein having an amino acid sequence indicated in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14 can be obtained from Arabidopsis thaliana in the form of cDNA or genomic DNA.

[0027] In addition, DNA encoding a protein having a modified amino acid sequence can be synthesized using commonly used site-specific mutagenesis or PCR method by using DNA having the inherent nucleotide sequence as a base. For example, a DNA fragment containing a desired modification can be obtained by obtaining a DNA fragment in which a modification is desired to be introduced by restriction enzyme treatment of the inherent cDNA or genomic DNA, and then performing site-specific mutagenesis or PCR method using this DNA as a template and a primer containing the desired mutation. Subsequently, this DNA fragment into which the mutation has been introduced should then be coupled with a DNA fragment that encodes another portion of the target protein.

[0028] Alternatively, in order to obtain DNA that encodes protein composed of a shortened amino acid sequence, DNA that encodes an amino acid sequence longer than the target amino acid sequence, such as the entire amino acid sequence, should be digested by a desired restriction enzyme and, if the resulting DNA fragment does not encode the entire target amino acid sequence, a DNA fragment composed of the portion of the sequence that is lacking should be synthesized and then coupled to that fragment.

[0029] Alternatively, cytokinin synthase or a protein having activity involved in cytokinin synthesis can also be obtained by using antibody to a protein having an amino acid sequence described in SEQ ID NO. 2, 4, 6, 8, 10, 12 or 14, and cytokinin synthase or protein having activity involved in cytokinin synthesis of other organisms can be cloned using antibody.

[0030] Thus, the present invention also relates to a recombinant vector, and particularly an expression vector, that contains the aforementioned gene, and to a host transformed by said vector. Procaryotic organisms or eucaryotic organisms can be used as hosts. Examples of prokaryotic organisms include bacteria such as Escherichia coli and other Escherichia species, Bacillus subtilis and other Bacillus species as well as other commonly used host microorganisms.

[0031] Examples of eucaryotic organisms include lower eucaryotic organisms such as eucaryotic microorganisms in the form of yeasts and molds. Examples of yeasts include Saccharomyces cerevisiae and other Saccharomyces species, while examples of molds include Aspergillus oryzae, Aspergillus niger and other Aspergillus species as well as Penicillium species. Moreover, plant cells and animal cells may also be used as hosts, examples of which include cells systems of animals cells such as mouse, hamster, monkey or human cells, and more specifically, COS cells, Vero cells, CHO cells, L cells, C127 cells, BALB/c 3T3 cells and Sp-2/0 cells. Examples of plant cells include tobacco and Arabidopsis cultured cells as well as cultured cells of poplar, eucalyptus and acacia species.

[0032] Moreover, insect cells such as silkworm (Bombyx mori) cells or adult silkworms themselves can be used as hosts. In addition, yoga (Spodoptera frugiprd) or cabbage looper (Trichoplusiani) cells can also be used.

[0033] Plasmids, phages, phagemids and viruses (such as Baculovirus (expression in insects) or Vaccinia virus (expression in animal cells)) can be used as expression vectors.

[0034] Expression vectors of the present invention contain expression control regions such as promoters, terminators, replication origins and so forth depending on the type of host into which they are to be introduced. Examples of promoters of bacterial expression vectors include lac promoter, examples of yeast promoters include glyceraldehyde 3-phosphate dehydrogenase promoter, PHO5 promoter, adhi promoter and pqk promoter, and examples of mold promoters include amylase promoter and trpC promoter.

[0035] In addition, examples of insect promoters include Baculovirus polyhedron promoter, and examples of animal cell promoters include Simian Virus 40 early and late promoters, CMV promoter, HSV-TK promoter or SRa promoter. Examples of plant promoters include the 35S promoter of cauliflower mosaic virus and nopaline synthase promoter, while examples of inductive promoters include glutathione-S-transferase II gene promoter, hsp80 promoter and ribulose 2-phosphate carboxylase small subunit gene promoter.

[0036] In addition, preferable modes of the expression vector include, in addition to those described above, those containing enhancers, splicing signals, poly A addition signals or selection markers (for example, dihydrofolic acid reductase genes (methotrexate resistant) and neo genes (G418 resistant)). Furthermore, in the case of using an enhancer, SV40 enhancer, for example, is inserted upstream or downstream from the gene.

[0037] Host transformation by an expression vector can be carried out in accordance with ordinary methods well known among persons with ordinary skill in the art, and these methods are described in, for example, Current Protocols in Molecular Biology, John Wiley & Sons Publishing, 1995. Culturing of the transformant can also be carried out in accordance with ordinary methods. Purification of protein involved in cytokinin synthesis from the culture can be carried out in accordance with ordinary methods for isolating and purifying proteins, examples of which include ultrafiltration and various types of column chromatography such as chromatography using Sepharose.

[0038] On the basis of the current level of technology, adventitious bud formation can be promoted even in plants such as roses, for which individual regeneration is difficult even by artificial regulation using plant hormones externally added to the medium, by inserting and expressing this gene in a plant by coupling this cDNA or gene under the control of a composite or inductive promoter with a system that uses Agrobacterium or a system that uses a particle gun or electroporation and so forth. Moreover, the various physiological actions exhibited by cytokinins in plants, such as lateral bud elongation, prevention of aging, flowering time, promotion of fruit enlargement and prevention of fruit dropping, can be regulated by controlling the expression of a gene that encodes a protein involved in cytokinin synthesis.

[0039] The following provides a detailed description of the present invention according to examples. Unless stated otherwise, molecular biological techniques are in accordance with Molecular Cloning (Sambrook, et al., 1989).

EXAMPLE 1 Search for and Isolation of Genes Encoding Proteins Involved in Cytokinin Synthesis

[0040] As a result of analyzing the amino acid sequences of the gene products of the tzs gene of Agrobacterium tumefaciens (Accession No. X03933-1, Protein ID No. CAA27572.1), the ipt gene of Agrobacterium tumefaciens (Accession No. AB025109-1, Protein ID No. BAA76344.1), the ptz gene of Pseudomonas syringae (Accession No. X03679-1, Protein ID No. CAA27315.1), the ipt gene of Rhodococcus faciens (Accession No. Z29635-4, Protein ID No. CAA82744.1), the dimethylallyl transferase gene of Erwinia herbicola (Accession No. Z46375-2, Protein ID No. CAA86510.1) and the δ-2-isopentenyl phosphate (IPP) transferase gene of Escherichia coli tRNA (Accession No. U14003-83, Protein ID No. AAA97067.1) using the amino acid sequence comparison software, Clustal V of Macvector 6.5.3, the preserved sequence of GxTxxGK[ST]xxxxx[VLI]xxxxxxx[VLI][VLI]xxDxxQx[57,60][VLI] [VLI]xGG[ST] was found. Here, x indicates an arbitrary amino acid, amino acid residues enclosed in brackets [ ] indicate which one of the amino acid residues contained therein, and [a,b] indicates the number of arbitrary types of amino acid residues greater than or equal to a but less than or equal to b.

[0041] Next, in order to isolate those genes or estimated gene regions considered to have this preserved amino acid sequence pattern, a search was made of the genomic database of Arabidopsis thaliana using the TAIR Pattern Matching Program. As a result, eight genes consisting of the estimated gene region numbers as designated by the National Genome Project of AT4g24650, T20010_(—)210, MDB19.12, MVI11.6, T26J14.3, F2J7.12, AF109376 and the 29375-30301 bp region of the T16G12 genome clone (Accession No. AC068809) were determined to have the aforementioned preserved amino acid sequence pattern.

[0042] Among these eight genes, cDNA has previously been cloned for AF109376 only, and is annotated as tRNA isopentenyl transferase mRNA. However, since the total length cDNA of AT4g24650, T20010_(—)210, MDB19.12, MVI11.6, T26J14.3 and F2J7.12 have not been isolated, they are annotated as probably being tRNA isopentenyl transferases. With respect to the 29375-30301 bp region of the genome clone of T16G12 (Accession No. AC068809), there are even no annotations regarding its estimated function. Namely, the functions of these eight genes are only estimated on the basis of computer analyses, while there have been no experimental analyses whatsoever, and their functions were not known. In addition, their enzyme activity has also not been measured, and their substrates have not been identified.

[0043] The nucleotide sequences of AT4g24650 (AtIPT4), T20010_(—)210 (AtIPT3), the cDNA corresponding to the 29375-30301 bp region of the genome clone of T16G12 (Accession No. AC068809) (AtIPT5), MDB19.12 (AtIPT7), MVI11.6 (AtIPT8), T26J14.3 (AtIPT1) and F2J7.12 (AtIPT6) are shown in SEQ ID NOs. 1, 3, 5, 7, 9, 11 and 13.

[0044] In addition, a molecular phylogenetic tree was produced with the Clustal W Program (http://www.ddbj.nig.ac.jp/E-mail/clustalw-e.html, Thompson, et al., 1994, Nucl. Acids Res., 22, 4673-4680), including each of the amino acids encoded by them (SEQ ID NOs. 2, 4, 6, 8, 10, 12 and 14) and homologous amino acid sequences obtained as a result of searching DNA databases (such as the DNA Databank of Japan (DDBJ) (http://www.ddbj.nig.ac.jp). As a result, the sequence indicated with SEQ ID NOs. 2, 4, 6, 8, 10, 12 and 14 were demonstrated to form a family with eucaryotic or bacterial DMAPP:tRNA isopentenyl transferase or isopentenyl transferase involved in cytokinin synthesis of plant pathogens such as Agrobacterium that form gall. Moreover, the amino acid sequences indicated in SEQ ID NOs. 2, 10, 12 and 14 formed a single subgroup. Those genes that were related to this subgroup consisted of AAL83819 (DDBJ accession no.) of petunia origin and BAB86364 (DDBJ accession no.) of rice origin. In addition, the amino acid sequences indicated in SEQ ID NOs. 4, 6 and 8 also formed a single subgroup, and AW720363 (DDBJ accession no.) of bird's-foot trefoil Lotus japonicus origin was positioned in this subgroup.

EXAMPLE 2 Excessive Expression in Plants of Genes Encoding Proteins Involved in Cytokinin Synthesis

[0045] i) Production of Gene Insertion Vector for Plants

[0046] pBI35T (WO 01/16332) was treated with EcoRI and HindIII to obtain a DNA fragment containing a promoter of cauliflower mosaic virus 35S RNA gene, a multi-cloning site and the terminator of 35S RNA gene. This was then treated with HindIII and EcoRI of pGPTV-KAN (Becker, R., et al., Plant Molecular Biology, 20, 1195-1197, 1992), and among the two fragments formed, the longer fragment was ligated to obtain pTK015 (FIG. 1). Similarly, this DNA fragment containing a promoter of cauliflower mosaic virus 35S RNA gene, a multi-cloning site and the terminator of 35S RNA gene was then treated with HindIII and EcoRI of pGPTV-Bar (Becker, R., et al., Plant Molecular Biology, 20, 1195-1197, 1992), and among the two fragments formed, the longer fragment was ligated to obtain pTK016.

[0047] For the predicted open reading frame of AF109376, DNA was amplified by incubating at 94° C. for 2 minutes followed by 40 cycles consisting of 15 seconds at 94° C., 30 seconds at 53° C. and 2 minutes and 40 seconds at 68° C. using the cDNA library of Arabidopsis thaliana for the template DNA of the PCR reaction, primer 398 (5′-TCCCCCGGGCGATGATGATGTTAAACCCTAGC-3′) (SEQ ID NO. 15) and primer 399 (5′-TCCCCCGGGTC AATTTACTTCTGCTTCTTGAACTTC) (SEQ ID NO. 16) as primers and pfx DNA polymerase (Gibco BRL), and purifying the amplified DNA followed by treatment with SmaI and repeated purification of the DNA. This was then cloned to the SmaI site of pTK015, after which the cloned product in the sense direction downstream from the 35S RNA gene promoter (35S promoter) of cauliflower mosaic virus was selected and designated as pTK015-AF109376.

[0048] AtIPT4 was amplified by incubating at 94° C. for 2 minutes followed by 42 cycles consisting of 15 seconds at 94° C., 20 seconds at 53° C. and 1 minute at 68° C. using the genomic DNA of Arabidopsis thaliana for the template of the PCR reaction, primer 421 (AAAATGAAGTGTAATGACAAAATGGTTGTG-3′) (SEQ ID NO. 17) and primer 407 (5′-GTCCAAACTAGTTAAGACTTAAAAATC-3′) (SEQ ID NO. 18) as primers and pfx DNA polymerase (Gibco BRL), followed by purification and cloning to the SmaI site of pTK015. The cloned product in the sense direction downstream from the 35S promoter was designated as pTK015-AtIPT4.

[0049] For AtIPT3, DNA was amplified using genomic DNA of Arabidopsis thaliana for the template, primer 703 (5′-CACCAGCAAGTTTATATTGCAAAGCGT-3′) (SEQ ID NO. 19) and primer 705 (5′-GTTGTAACCACGTAAAAGATAAGGGTG-3′) (SEQ ID NO. 20) as primers and Herculase (trade name, Stratagene) as heat-resistant DNA synthase. The PCR reaction was carried out for 1 minute at 92° C. followed by 35 cycles consisting of 30 seconds at 92° C., 30 seconds at 55° C. and 2 minutes and 30 seconds at 70° C. Following purification of this product, it was cloned at the blunt terminal to the SmaI site of pTK016, and the cloned product of AtIPT3 in the sense direction downstream from the 35S promoter was selected and designated as pTK016-AtIPT3.

[0050] For pTK015, after digesting with SmaI and KpnI, the DNA was purified using the QUIAquick PCR Purification Kit (Qiagen). Here, the sequence of the multi-cloning site was altered by cloning primer 852 (5′-CTCGAGTTGGCGCGCCACCCGGGATTAATTAAGAC TAGTGGGTAC-3′) (SEQ ID NO. 27) and primer 853 (5′-CCCACTAGTCTTAATTAA TCCCGGGTGGCGCGCCAACTCGAG-3′) (SEQ ID NO. 28). Here, since primer 852 and primer 853 are synthetic DNA having mutually complementary sequences, this procedure was carried out by incubating the three elements consisting of a fragment obtained by digesting pTK015 with SmaI and KpnI, primer 852 and primer 853 in the presence of ligase under ordinary conditions. The plasmid produced in this manner was designated as pHM4. The only difference between pHM4 and pTK015 is the sequence of the multi--cloning site. Those unique sites present in the multi-cloning site of pTK015 consist of XbaI, XhoI, SmaI, PacI, SpeI, KpnI and SalI.

[0051] 4 μg of pHM4 were digested with 20 units of BamHI. The terminals were blunted by incubating half the amount for 30 minutes at 70° C. in the presence of 200 μM deoxyATP, deoxyTTP, deoxyCTP, deoxyGTP and 1 unit of pfu DNA polymerase (Stratagene). After treating this for 1 hour at 37° C. with 20 units of calf intestine alkaline phosphatase (Takara), the DNA was purified using the QUIAquick PCR Purification Kit (Qiagen). Here, the cloned DNA fragment that was amplified (for 35 cycles consisting of 20 seconds at 94° C., 30 seconds at 55° C. and 1 minute at 72° C.) from genomic DNA of Arabidopsis thaliana using Herculase heat-resistant DNA polymerase (Stratagene), primer 918 (5′-ATG ACA GAA CTC AAC TTC CAC CT-3′) (SEQ ID NO. 29) and primer 879 (5′-CAAAAAAAAGATCTAATTTTGCACCAAATGCCGCTT-31) (SEQ ID NO. 30) was cloned and designated as pHM4-AtIPT1.

[0052] A cloned DNA fragment amplified from the genomic DNA of Arabidopsis thaliana using primer 533 (5′-ATTATGCAAAATCTTACG TCCACATTCGTC-3′) (SEQ ID NO. 31) and primer 881 (5′-ACAGGATCCTCACACTTTGTCTTTCACCAAG-31) (SEQ ID NO. 32) was cloned in the same manner as the production of pHM4-AtIPT1 and designated as pHM4-AtIPT8.

[0053] A sequence containing the entire code region of SEQ ID NO. 6 starting 66 bps upstream from the translation starting point ATG described in SEQ ID NO. 5 was amplified by PCR using genomic DNA extracted from a Columbia wild strain (Takara Shuzo) as a template and using primer 856 (5′-CCGCTCGAGA TGAAGCCATGCATGACGGCTC-3′) (SEQ ID NO. 33) and primer 857 (5′-GGACTAGTCACCGGGAAATCGCCGCCA-3′) (SEQ ID NO. 34). These primers contain restriction enzyme sites and were treated with XhoI and SpeI following PCR. This DNA fragment was cloned to pHM4, a vector excessive expression in plants, and designated as pHM4-AtIPT5.

[0054] ii) Gene Insertion into Plants

[0055] pTK015, pTK015-AF109376, pTK015-AtIPT4 and pTK016-AtIPT3 were inserted into the callus of Arabidopsis thaliana using Agrobacterium. The method for inserting genes using Agrobacterium was in accordance with the method of Akama, et al. (Akama, K. et al., 1992 Plant Cell Rep., 12, 7-11). The calli containing the inserted genes were cultured in two types of media consisting of cytokinin-free medium [GM medium (Akama, K. et al., 1992 Plant Cell Rep., 12, 7-11) containing 50 μg/ml of kanamycin sulfate, 100 μg/ml of cefotaxime, 100 μg/ml of vancomycin and 0.3 μg/ml of indole acetate] and cytokinin-containing medium (cytokinin-free medium containing 0.5 μg/ml of trans-zeatin). When observed two weeks later, neither the calli transformed with pTK015 or calli transformed with pTK015-AF109376 formed shoots in the cytokinin-free medium, and only formed shoots in the cytokinin-containing medium. In contrast, the calli transformed with pTK015-AtIPT4 formed shoots in both the cytokinin-free and cytokinin-containing medium. In addition, calli transformed with pTK016-AtIPT3 similarly formed shoots in both the cytokinin-free and cytokinin-containing media.

[0056] In addition, calli of Arabidopsis thaliana respectively inserted with pHM4, pHM4-AtIPT1, pHM4-AtIPT8 and pHMR-AtIPT5 were cultured in cytokinin-free medium containing 0.2 μg/ml of indole acetate, 501g/ml of kanamycin and 100 μg/ml of claforan. The procedure was the same as the example in which AtIPT4 was inserted into calli. Although the calli containing pHM4 did not form shoots, the calli containing pHM4-AtIPT1, pHM4-AtIPT8 and pHM4-AtIPT5 formed shoot tissue.

[0057] On the basis of these findings, AtIPT4 and AtIPT3 were suggested to have the ability to induce shoots and the ability to synthesis cytokinins.

[0058] In addition, it was also indicated that excessive expression of AtIPT1, AtIPT5 and AtIPT3 is capable of causing a cytokinin response.

[0059] iii) Excessive Expression of pHM4-AtIPT5 in Plants

[0060] pHM4-AtIPT5 was transformed in Arabidopsis thaliana using the vacuum infiltration Agrobacterium infection method (O. Araki, Shujunsha Publishing, Cell Engineering Supplement, Plant Cell Engineering Series 4, Experimental Protocols in Model Plants, p. 109-113). The resulting seeds were cultivated in MS agar medium containing 50 μg/ml of kanamycin followed by selection of transformants. When the transformants were cultivated in vermiculite containing one-half the concentration of MS medium, an extremely large number of lateral buds were formed in several of the plants (causing the plants to appear bushy) (FIG. 2). This phenotype was not observed in pHM4 transformants cultivated as a control. As a result, it was determined that when AtIPT5 is expressed in excess, terminal bud dominance diminishes and lateral bud formation is promoted.

EXAMPLE 3 Measurement of Enzyme Activity of Proteins Involved in Cytokinin Synthesis

[0061] i) Plasmid Production for Measuring Enzyme Activity

[0062] The code region was amplified by using the pTK015-AtIPT4 produced in Example 2 as a template, using primer 480 (5′-GGAATTCCATATGAAGTGTAATGACAAAATGGTTG{circumflex over ( )}3′) (SEQ ID NO. 21) and primer 481 (5′-GAAGATCTGTCCAAACTAGTTAAGACTTAAAAA TC-3′) (SEQ ID NO. 22) as primers, and using LA taq (Takara Shuzo). After purifying the amplified region, it was treated with NdeI and BglII followed by again purifying the DNA. This DNA fragment was cloned between the NdeI and BamHI sites of pET16b (Novagen) to produce pET16b-AtIPT4.

[0063] In addition, the coding region was amplified using pTK015-AF109376 as the template for the PCR reaction, using primer 550 (5′-GATCCCCGGCATATGATGATGTTAAACCCTAGC-18-3′) (SEQ ID NO. 23) and primer 551 (5′-ACGGTACCCATA TGTCAATTTACTTCTGCTTCTTGAAC-3′) (SEQ ID NO. 24) as primers, and using Herculase (Stratagene) as heat-resistant DNA polymerase. This was then treated with NdeI and cloned to the NdeI site of pET16b to produce pET16b-AF109376.

[0064] Moreover, the coding region was amplified using genomic DNA of Arabidopsis thaliana as the template for the PCR reaction, using primer 741 (5′-TTATACATATGAAGCCATGCATGACGGCTCTAAG-3′) (SEQ ID NO. 25) and primer 742 (5′-CGGGATCCTCACCGGG AAATCGCCGCCA-3′) (SEQ ID NO. 26) as primers, and using LA taq (Takara Shuzo) as heat-resistant enzyme. Following purification, the DNA was treated with NdeI and BamHI and cloned between the NdeI and BamHI sites of pET15b (Novagen) to produce pET15b-AtIPT5.

[0065] ii) Measurement of Enzyme Activity of E. Coli Extract As was previously described, AtIPT1, AtIPT4, AtIPT8 and AtIPT6 form a single subgroup, while AtIPT3, AtIPT5 and AtIPT7 form a different subgroup. Enzyme activity in E. coli was measured from each for a single gene.

[0066] After culturing E. coli strain AD494(DE3)pLysS containing pET16b-AtIPT4, pET16b-AF109376 or pET15b-AtIPT5 for 12 hours at 20° C. in the presence of 1 mM IPTG, the microorganisms were collected by centrifugation, and after adding Buffer A (25 mM Tris-HCl, 50 mM KCl, 5 mM β-mercaptoethanol, 1 mM PMSF and 20 μg/ml of leupeptin) to an OD600 of 100, the E. coli were disrupted by freezing and thawing. The disrupted E. coli were then centrifuged for 10 minutes at 300000 g followed by recovery of the supernatants. 10 μl of these supernatants were mixed with Buffer A containing 60 μM DMAPP, 5 μM [3H]AMP (722 GBq/mmol) and 10 mM MgCl₂ followed by incubation for 30 minutes at 25° C. Subsequently, 50 mM of Tris-HCl (pH 9) was added to this reaction liquid followed by the addition of calf intestine alkaline phosphatase to a concentration of 2 units/30 μl and incubating for 30 minutes at 37° C. to carry out a dephosphatization reaction. As a result of developing the reaction liquid by C18 reversed-phase thin layer chromatography (mobile phase: 50% methanol) and detecting the reaction products by autoradiography, formation of isopentenyl adenosine was confirmed in the reaction liquids containing extracts of E. coli having pET16b-AtIPT4 and pET15b-AtIPT5. However, formation activity of isopentenyl adenosine was not observed in the extract of E. coli containing pET16b-AF109376.

[0067] iii) Measurement of Enzyme Activity of Purified Proteins

[0068] Similar to Example 3, Part (i), AtIPT4 was cloned in pET32b (Novagen) and an extract was prepared from E. coli in the same manner as Example 3, Part (ii). This was designated as Sample A. 400 μl of Ni-NTA agarose suspension (containing 110 μl of Ni-NTA agarose as precipitate, 30 mM NaH₂PO₄ (pH 8), 15 mM indazole, 0.9 M NaCl, 7.5 mM β-mercaptoethanol, 0.5 mM PMSF and 30 μg/ml of leupeptin) were added to 800 μl of Sample A. This suspension was designated as Sample B. Sample B was then centrifuged to separate into supernatant (Sample C) and precipitate. Washing liquid (consisting of 20 mM NaH₂PO₄ (pH 8), 10 mM indazole, 0.3 M NaCl, 5 mM β-mercaptoethanol, 0.5 mM PMSF and 10 μg/ml of leupeptin) was added to the precipitate, and the Ni-NTA agarose was washed four times using a procedure in which the precipitate was recovered by centrifugation. This Ni-NTA agarose was then suspended in 500 μl of washing liquid and designated as Sample D. 50 μl of Sample D were then mixed with 50 μl of 2× reaction liquid (25 mM Tris-HCl (pH 7.5), 75 mM KCl, 10 mM MgCl₂, 10 μg/ml of leupeptin, 1 mM PMSF and 66 μM DMAPP) containing one of the nucleotides of ATP, ADP or AMP or adenosine or adenine at 0.25 μM, which were labeled with ³H, and allowed to react for 30 minutes at 23° C. After adding 700 μl of ethyl acetate to this reaction liquid followed by stirring and centrifuging, 550 μl of the ethyl acetate layer were recovered followed by the addition of 500 μl of distilled water. After stirring and centrifugal separation, 350 μl of the ethyl acetate layer were recovered followed again by the addition of 500 μl of distilled water. After again stirring and separating by centrifugation, 0.5 ml of ACSII (Pharmacia) were added to 50 μl of the ethyl acetate layer followed by measurement of radioactivity with a liquid scintillation counter. As a result, the dimethylallyl group of DMAPP was found to have efficiently transferred to ATP and ADP. Thus, it was shown that the AtIPT4 product has activity that transfers a dimethylallyl group to ATP and ADP.

[0069] When the Km for ATP was measured in the presence of 0.4 mM DMAPP using purified recombinant AtIPT4 protein (2 ng/ml), the resulting value was comparable to the Km of 11.1 μM (Morris, et al., Aust. J. Plant Physiol., 20, 621-637, 1993) of tzs for AMP. In addition, when the Km for DMAPP was measured in the presence of 200 μM ATP, the value was 6.5 μM.

[0070] Similarly, AtIPT1 also encoded protein having activity that transfers a dimethylallyl group to ATP and ADP.

[0071] iv) Identification of Reaction Products

[0072] The aforementioned Sample D was mixed with an equal volume of 2× reaction liquid (containing 1 mM ATP and 1 mM DMAPP) and allowed to react for 1 hour at 25° C. After centrifuging, the supernatant was divided into two equal portions, and one of the portions was treated with calf intestine alkaline phosphatase in the same manner as previously described. After diluting each portion with 3 volumes of acetone and holding for 30 minutes at −80° C., they were centrifuged for 30 minutes at 17,000×g to remove the protein. After drying the supernatant to a solid under reduced pressure, it was dissolved in methanol. A portion of the dried supernatant was fractionated with the Chemocobond ODS-W column (Chemco). Elution was carried out using a linear concentration gradient by first eluting for 15 minutes with 20 mM KH₂PO₄ followed by 30 minutes with an 80% aqueous acetonitrile solution containing K₂HPO₄ ranging from 20 mM to 4 mM. The sample not treated with calf intestine alkaline phosphatase exhibited two main peaks in Chemocobond ODS-W column chromatography. The retention time of the peak that eluted first coincided with the retention time of ATP. The retention time of the peak (Peak A) that eluted later did not coincide with any of the retention times of ATP, adenosine or isopentenyl adenosine. The sample treated with calf intestine alkaline phosphatase also exhibited two main peaks in Chemocobond ODS-W column chromatography. The retention time of the peak that eluted first coincided with the retention time of adenosine, while the retention time of the peak that eluted later (Peak B) coincided with that of isopentenyl adenosine.

[0073] After drying the fractions of Peaks A and B, they were dissolved in ethanol and analyzed by fast atom bombardment mass spectrometry (JMS-SX102 or JEOL Mstation, JOEL Datum Ltd.). As a result, a signal originating in the compound of Peak A was unable to be obtained, because of inhibition of ionization by the triphosphate group. Signals originating in the compound of Peak B were observed at m/z values of 336 and 204, with the former corresponding to isopentenyl adenosine, and the latter corresponding to a decomposition product of isopentenyl adenosine. On the basis of the above, Peak A was thought to be isopentenyl ATP (also referred to as iPTP), which is a compound resulting from the phosphatization of isopentenyl adenosine.

[0074] When the genes indicated with SEQ ID NOs. 2 and 6 were expressed in E. coli, both exhibited cytokinin synthesis activity. In addition, a cytokinin response was evoked in the case of excessive expression in plants of enzymes of the genes indicated in SEQ ID NOs. 2, 4, 6, 10 and 12. In addition, SEQ ID NOs. 2, 10, 12 and 14 or SEQ ID NOs. 4, 6 and 8 were clearly shown to be extremely closely related in terms of their respective molecular systems. Thus, each of these are considered to be cytokinin synthesis enzymes. Thus, it was possible to control cell division, differentiation, axillary bud length, regulation of nutrient distribution, inhibition of aging, reproductive growth and seed growth by controlling the expression of the genes of the present invention and their analogous genes. In addition, since they are plant genes, the appearance of toxicity and so forth of proteins expressed in plants into which these genes have been inserted is unlikely.

[0075] Since ATP can be efficiently used as a substrate of cytokinin synthesis, these genes are expected to function more effectively in plants than cytokinin synthesis genes originating in bacteria using AMP as substrate.

0 SEQUENCE LISTING <160> NUMBER OF SEQ ID NOS: 34 <210> SEQ ID NO 1 <211> LENGTH: 957 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT4) <400> SEQUENCE: 1 atg aag tgt aat gac aaa atg gtt gtg atc atg ggt gcc acc ggt tct 48 Met Lys Cys Asn Asp Lys Met Val Val Ile Met Gly Ala Thr Gly Ser 1 5 10 15 ggc aag tca tca ctc tct gtt gat ctc gct tta cat ttt aaa gcc gag 96 Gly Lys Ser Ser Leu Ser Val Asp Leu Ala Leu His Phe Lys Ala Glu 20 25 30 atc atc aac tct gac aaa atg cag ttc tac gat ggc ttg aag atc acc 144 Ile Ile Asn Ser Asp Lys Met Gln Phe Tyr Asp Gly Leu Lys Ile Thr 35 40 45 acg aat caa tcg acc att gaa gat cga cgt gga gtg cca cat cac ctt 192 Thr Asn Gln Ser Thr Ile Glu Asp Arg Arg Gly Val Pro His His Leu 50 55 60 ctc ggt gaa cta aac ccg gag gct gga gaa gtc aca gcg gca gaa ttt 240 Leu Gly Glu Leu Asn Pro Glu Ala Gly Glu Val Thr Ala Ala Glu Phe 65 70 75 80 cgc gtt atg gcg gct gaa gcc atc tcc gag att act caa cgt aaa aag 288 Arg Val Met Ala Ala Glu Ala Ile Ser Glu Ile Thr Gln Arg Lys Lys 85 90 95 ctc cca atc ctt gcc ggt gga tcc aac tca tac att cat gct ctc ctt 336 Leu Pro Ile Leu Ala Gly Gly Ser Asn Ser Tyr Ile His Ala Leu Leu 100 105 110 gca aaa tct tat gac cct gaa aac tat ccg ttt tct gat cac aag ggc 384 Ala Lys Ser Tyr Asp Pro Glu Asn Tyr Pro Phe Ser Asp His Lys Gly 115 120 125 tca atc tgc tcc gag ttg aaa tat gat tgt tgt ttc att tgg ata gat 432 Ser Ile Cys Ser Glu Leu Lys Tyr Asp Cys Cys Phe Ile Trp Ile Asp 130 135 140 gtg gat cag tct gtg tta ttc gag tat ctt tct tta cgt ttg gat ctt 480 Val Asp Gln Ser Val Leu Phe Glu Tyr Leu Ser Leu Arg Leu Asp Leu 145 150 155 160 atg atg aag tca ggt atg ttc gag gag atc gct gag ttc cac cgc tct 528 Met Met Lys Ser Gly Met Phe Glu Glu Ile Ala Glu Phe His Arg Ser 165 170 175 aag aag gcc ccg aaa gag cca ttg ggg ata tgg aag gct ata gga gtg 576 Lys Lys Ala Pro Lys Glu Pro Leu Gly Ile Trp Lys Ala Ile Gly Val 180 185 190 caa gag ttt gat gac tac ctc aaa atg tac aag tgg gac aat gac atg 624 Gln Glu Phe Asp Asp Tyr Leu Lys Met Tyr Lys Trp Asp Asn Asp Met 195 200 205 gat aaa tgg gac cct atg aga aag gag gct tat gag aag gcg gtg aga 672 Asp Lys Trp Asp Pro Met Arg Lys Glu Ala Tyr Glu Lys Ala Val Arg 210 215 220 gcc atc aaa gaa aac aca ttt cag ctc aca aag gat caa atc acg aag 720 Ala Ile Lys Glu Asn Thr Phe Gln Leu Thr Lys Asp Gln Ile Thr Lys 225 230 235 240 atc aac aag ctg aga aat gcc ggg tgg gac ata aag aag gtg gat gct 768 Ile Asn Lys Leu Arg Asn Ala Gly Trp Asp Ile Lys Lys Val Asp Ala 245 250 255 aca gca tcg ttt cga gag gca att agg gca gcc aag gaa ggc gaa ggt 816 Thr Ala Ser Phe Arg Glu Ala Ile Arg Ala Ala Lys Glu Gly Glu Gly 260 265 270 gta gcc gag atg cag aga aag ata tgg aac aag gaa gtg ttg gaa ccg 864 Val Ala Glu Met Gln Arg Lys Ile Trp Asn Lys Glu Val Leu Glu Pro 275 280 285 tgt gtg aag att gtc agg agc cac ttg gac caa ccg atc aac tat tat 912 Cys Val Lys Ile Val Arg Ser His Leu Asp Gln Pro Ile Asn Tyr Tyr 290 295 300 tat tat tac ttt tat tta cta aaa aga ttt tta agt ctt aac tag 957 Tyr Tyr Tyr Phe Tyr Leu Leu Lys Arg Phe Leu Ser Leu Asn 305 310 315 <210> SEQ ID NO 2 <211> LENGTH: 318 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT4) <400> SEQUENCE: 2 Met Lys Cys Asn Asp Lys Met Val Val Ile Met Gly Ala Thr Gly Ser 1 5 10 15 Gly Lys Ser Ser Leu Ser Val Asp Leu Ala Leu His Phe Lys Ala Glu 20 25 30 Ile Ile Asn Ser Asp Lys Met Gln Phe Tyr Asp Gly Leu Lys Ile Thr 35 40 45 Thr Asn Gln Ser Thr Ile Glu Asp Arg Arg Gly Val Pro His His Leu 50 55 60 Leu Gly Glu Leu Asn Pro Glu Ala Gly Glu Val Thr Ala Ala Glu Phe 65 70 75 80 Arg Val Met Ala Ala Glu Ala Ile Ser Glu Ile Thr Gln Arg Lys Lys 85 90 95 Leu Pro Ile Leu Ala Gly Gly Ser Asn Ser Tyr Ile His Ala Leu Leu 100 105 110 Ala Lys Ser Tyr Asp Pro Glu Asn Tyr Pro Phe Ser Asp His Lys Gly 115 120 125 Ser Ile Cys Ser Glu Leu Lys Tyr Asp Cys Cys Phe Ile Trp Ile Asp 130 135 140 Val Asp Gln Ser Val Leu Phe Glu Tyr Leu Ser Leu Arg Leu Asp Leu 145 150 155 160 Met Met Lys Ser Gly Met Phe Glu Glu Ile Ala Glu Phe His Arg Ser 165 170 175 Lys Lys Ala Pro Lys Glu Pro Leu Gly Ile Trp Lys Ala Ile Gly Val 180 185 190 Gln Glu Phe Asp Asp Tyr Leu Lys Met Tyr Lys Trp Asp Asn Asp Met 195 200 205 Asp Lys Trp Asp Pro Met Arg Lys Glu Ala Tyr Glu Lys Ala Val Arg 210 215 220 Ala Ile Lys Glu Asn Thr Phe Gln Leu Thr Lys Asp Gln Ile Thr Lys 225 230 235 240 Ile Asn Lys Leu Arg Asn Ala Gly Trp Asp Ile Lys Lys Val Asp Ala 245 250 255 Thr Ala Ser Phe Arg Glu Ala Ile Arg Ala Ala Lys Glu Gly Glu Gly 260 265 270 Val Ala Glu Met Gln Arg Lys Ile Trp Asn Lys Glu Val Leu Glu Pro 275 280 285 Cys Val Lys Ile Val Arg Ser His Leu Asp Gln Pro Ile Asn Tyr Tyr 290 295 300 Tyr Tyr Tyr Phe Tyr Leu Leu Lys Arg Phe Leu Ser Leu Asn 305 310 315 <210> SEQ ID NO 3 <211> LENGTH: 1011 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT3) <400> SEQUENCE: 3 atg atc atg aag ata tct atg gct atg tgc aaa caa cca ttg cct cct 48 Met Ile Met Lys Ile Ser Met Ala Met Cys Lys Gln Pro Leu Pro Pro 1 5 10 15 tcg ccg act tta gac ttc cct cca gcg aga ttt ggt ccc aat atg cta 96 Ser Pro Thr Leu Asp Phe Pro Pro Ala Arg Phe Gly Pro Asn Met Leu 20 25 30 act cta aac cca tac ggt cca aag gac aaa gtt gtg gtc atc atg ggt 144 Thr Leu Asn Pro Tyr Gly Pro Lys Asp Lys Val Val Val Ile Met Gly 35 40 45 gct acc ggg aca ggc aag tca cga ctc tcc gtg gat ata gcc aca cgt 192 Ala Thr Gly Thr Gly Lys Ser Arg Leu Ser Val Asp Ile Ala Thr Arg 50 55 60 ttt cgg gct gag atc ata aac tca gac aag ata caa gtc cac caa ggt 240 Phe Arg Ala Glu Ile Ile Asn Ser Asp Lys Ile Gln Val His Gln Gly 65 70 75 80 cta gac att gta acc aac aag atc acg agc gag gag agc tgc ggg gta 288 Leu Asp Ile Val Thr Asn Lys Ile Thr Ser Glu Glu Ser Cys Gly Val 85 90 95 ccg cac cat ctc ctc ggc gtc ttg ccg cct gaa gcc gac tta acc gcc 336 Pro His His Leu Leu Gly Val Leu Pro Pro Glu Ala Asp Leu Thr Ala 100 105 110 gcg aat tac tgt cac atg gcg aat ctc tcc att gaa tcc gtc cta aac 384 Ala Asn Tyr Cys His Met Ala Asn Leu Ser Ile Glu Ser Val Leu Asn 115 120 125 cgt gga aag ctt cca atc atc gtt gga ggt tcc aac tct tac gtg gag 432 Arg Gly Lys Leu Pro Ile Ile Val Gly Gly Ser Asn Ser Tyr Val Glu 130 135 140 gct cta gtg gat gac aaa gaa aac aag ttc agg tcg aga tac gac tgt 480 Ala Leu Val Asp Asp Lys Glu Asn Lys Phe Arg Ser Arg Tyr Asp Cys 145 150 155 160 tgt ttt cta tgg gtg gac gtg gca ctt ccc gtt ttg cac ggg ttc gtg 528 Cys Phe Leu Trp Val Asp Val Ala Leu Pro Val Leu His Gly Phe Val 165 170 175 tct gag aga gtt gac aag atg gtg gag agt gga atg gtt gag gaa gtc 576 Ser Glu Arg Val Asp Lys Met Val Glu Ser Gly Met Val Glu Glu Val 180 185 190 aga gaa ttt ttc gac ttt tcg aac tct gat tac tca aga ggg atc aag 624 Arg Glu Phe Phe Asp Phe Ser Asn Ser Asp Tyr Ser Arg Gly Ile Lys 195 200 205 aaa gca atc gga ttt ccg gag ttt gac agg ttt ttc agg aac gag cag 672 Lys Ala Ile Gly Phe Pro Glu Phe Asp Arg Phe Phe Arg Asn Glu Gln 210 215 220 ttc ttg aat gtg gaa gac aga gaa gaa ctg tta agt aaa gtg ttg gaa 720 Phe Leu Asn Val Glu Asp Arg Glu Glu Leu Leu Ser Lys Val Leu Glu 225 230 235 240 gaa ata aag agg aat aca ttt gag tta gct tgt agg cag aga gaa aag 768 Glu Ile Lys Arg Asn Thr Phe Glu Leu Ala Cys Arg Gln Arg Glu Lys 245 250 255 atc gaa cgg ttg aga aaa gtg aag aag tgg tct att cag aga gtg gat 816 Ile Glu Arg Leu Arg Lys Val Lys Lys Trp Ser Ile Gln Arg Val Asp 260 265 270 gcg act cca gtc ttt aca aag cga agg tcc aag atg gat gct aac gtg 864 Ala Thr Pro Val Phe Thr Lys Arg Arg Ser Lys Met Asp Ala Asn Val 275 280 285 gcc tgg gag agg ctc gtg gct gga cca agc aca gat act gtg tcg cgg 912 Ala Trp Glu Arg Leu Val Ala Gly Pro Ser Thr Asp Thr Val Ser Arg 290 295 300 ttt ctg ctg gac att gcc agc cga cga ccg ctc gtg gaa gct tca aca 960 Phe Leu Leu Asp Ile Ala Ser Arg Arg Pro Leu Val Glu Ala Ser Thr 305 310 315 320 gcg gtt gcg gcc gcc atg gaa cgc gag ttg tcg cgg tgt cta gtg gcg 1008 Ala Val Ala Ala Ala Met Glu Arg Glu Leu Ser Arg Cys Leu Val Ala 325 330 335 tga 1011 <210> SEQ ID NO 4 <211> LENGTH: 336 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT3) <400> SEQUENCE: 4 Met Ile Met Lys Ile Ser Met Ala Met Cys Lys Gln Pro Leu Pro Pro 1 5 10 15 Ser Pro Thr Leu Asp Phe Pro Pro Ala Arg Phe Gly Pro Asn Met Leu 20 25 30 Thr Leu Asn Pro Tyr Gly Pro Lys Asp Lys Val Val Val Ile Met Gly 35 40 45 Ala Thr Gly Thr Gly Lys Ser Arg Leu Ser Val Asp Ile Ala Thr Arg 50 55 60 Phe Arg Ala Glu Ile Ile Asn Ser Asp Lys Ile Gln Val His Gln Gly 65 70 75 80 Leu Asp Ile Val Thr Asn Lys Ile Thr Ser Glu Glu Ser Cys Gly Val 85 90 95 Pro His His Leu Leu Gly Val Leu Pro Pro Glu Ala Asp Leu Thr Ala 100 105 110 Ala Asn Tyr Cys His Met Ala Asn Leu Ser Ile Glu Ser Val Leu Asn 115 120 125 Arg Gly Lys Leu Pro Ile Ile Val Gly Gly Ser Asn Ser Tyr Val Glu 130 135 140 Ala Leu Val Asp Asp Lys Glu Asn Lys Phe Arg Ser Arg Tyr Asp Cys 145 150 155 160 Cys Phe Leu Trp Val Asp Val Ala Leu Pro Val Leu His Gly Phe Val 165 170 175 Ser Glu Arg Val Asp Lys Met Val Glu Ser Gly Met Val Glu Glu Val 180 185 190 Arg Glu Phe Phe Asp Phe Ser Asn Ser Asp Tyr Ser Arg Gly Ile Lys 195 200 205 Lys Ala Ile Gly Phe Pro Glu Phe Asp Arg Phe Phe Arg Asn Glu Gln 210 215 220 Phe Leu Asn Val Glu Asp Arg Glu Glu Leu Leu Ser Lys Val Leu Glu 225 230 235 240 Glu Ile Lys Arg Asn Thr Phe Glu Leu Ala Cys Arg Gln Arg Glu Lys 245 250 255 Ile Glu Arg Leu Arg Lys Val Lys Lys Trp Ser Ile Gln Arg Val Asp 260 265 270 Ala Thr Pro Val Phe Thr Lys Arg Arg Ser Lys Met Asp Ala Asn Val 275 280 285 Ala Trp Glu Arg Leu Val Ala Gly Pro Ser Thr Asp Thr Val Ser Arg 290 295 300 Phe Leu Leu Asp Ile Ala Ser Arg Arg Pro Leu Val Glu Ala Ser Thr 305 310 315 320 Ala Val Ala Ala Ala Met Glu Arg Glu Leu Ser Arg Cys Leu Val Ala 325 330 335 <210> SEQ ID NO 5 <211> LENGTH: 990 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT5) <400> SEQUENCE: 5 atg aag cca tgc atg acg gct cta aga caa gtg att caa cca ttg tcg 48 Met Lys Pro Cys Met Thr Ala Leu Arg Gln Val Ile Gln Pro Leu Ser 1 5 10 15 ttg aac ttc caa gga aac atg gtg gac gtt ccg ttt ttc cgg cga aaa 96 Leu Asn Phe Gln Gly Asn Met Val Asp Val Pro Phe Phe Arg Arg Lys 20 25 30 gac aag gtt gtt ttc gtc atg gga gcc acc gga acc ggc aaa tct cgt 144 Asp Lys Val Val Phe Val Met Gly Ala Thr Gly Thr Gly Lys Ser Arg 35 40 45 cta gcc att gac cta gcc act cgt ttt ccg gcg gag att gta aac tcc 192 Leu Ala Ile Asp Leu Ala Thr Arg Phe Pro Ala Glu Ile Val Asn Ser 50 55 60 gac aag atc cag gtc tat aaa ggt cta gac att gtg act aac aaa gtc 240 Asp Lys Ile Gln Val Tyr Lys Gly Leu Asp Ile Val Thr Asn Lys Val 65 70 75 80 act cct gag gaa agc ctt ggc gtt cct cac cac ctt ctc ggc acc gtc 288 Thr Pro Glu Glu Ser Leu Gly Val Pro His His Leu Leu Gly Thr Val 85 90 95 cac gac act tac gaa gat ttc acg gcg gag gat ttt cag cgt gaa gca 336 His Asp Thr Tyr Glu Asp Phe Thr Ala Glu Asp Phe Gln Arg Glu Ala 100 105 110 atc agg gcc gtc gag tca atc gtc cag aga gac cgt gtc ccg atc ata 384 Ile Arg Ala Val Glu Ser Ile Val Gln Arg Asp Arg Val Pro Ile Ile 115 120 125 gcc ggt ggt tcc aat tct tac atc gag gct ctg gtc aac gat tgc gtt 432 Ala Gly Gly Ser Asn Ser Tyr Ile Glu Ala Leu Val Asn Asp Cys Val 130 135 140 gac ttc cgg tta agg tat aat tgt tgc ttc ttg tgg gtc gac gtc tct 480 Asp Phe Arg Leu Arg Tyr Asn Cys Cys Phe Leu Trp Val Asp Val Ser 145 150 155 160 aga ccg gtt tta cac tcg ttt gtc tcg gag cga gtt gat aag atg gtt 528 Arg Pro Val Leu His Ser Phe Val Ser Glu Arg Val Asp Lys Met Val 165 170 175 gat atg ggt ctc gtc gac gag gtt cgc cgc atc ttc gat ccg tct tcg 576 Asp Met Gly Leu Val Asp Glu Val Arg Arg Ile Phe Asp Pro Ser Ser 180 185 190 tcg gat tac tcc gct gga att cgc cga gcc att gga gtt cca gag ctc 624 Ser Asp Tyr Ser Ala Gly Ile Arg Arg Ala Ile Gly Val Pro Glu Leu 195 200 205 gac gaa ttt ctc cgt tcg gag atg cgg aat tat ccg gcg gag acg acg 672 Asp Glu Phe Leu Arg Ser Glu Met Arg Asn Tyr Pro Ala Glu Thr Thr 210 215 220 gag aga ctt ctt gaa acg gcg atc gag aag att aaa gag aac act tgt 720 Glu Arg Leu Leu Glu Thr Ala Ile Glu Lys Ile Lys Glu Asn Thr Cys 225 230 235 240 ttg ctt gcg tgt aga caa ttg cag aag att caa agg ctt tac aag cag 768 Leu Leu Ala Cys Arg Gln Leu Gln Lys Ile Gln Arg Leu Tyr Lys Gln 245 250 255 tgg aag tgg aac atg cac cgt gtc gac gcg acg gag gtt ttt ctc cga 816 Trp Lys Trp Asn Met His Arg Val Asp Ala Thr Glu Val Phe Leu Arg 260 265 270 cga gga gaa gaa gct gat gag gct tgg gat aac tca gtg gct cat ccg 864 Arg Gly Glu Glu Ala Asp Glu Ala Trp Asp Asn Ser Val Ala His Pro 275 280 285 agc gca ctc gcc gtc gaa aag ttc ctt agt tac agc gat gac cac cat 912 Ser Ala Leu Ala Val Glu Lys Phe Leu Ser Tyr Ser Asp Asp His His 290 295 300 ttg gaa ggc gcc aat att ctc cta ccg gag atc tct gcc gtt ccg cct 960 Leu Glu Gly Ala Asn Ile Leu Leu Pro Glu Ile Ser Ala Val Pro Pro 305 310 315 320 ctt cca gcc gcc gtg gcg gcg att tcc cgg 990 Leu Pro Ala Ala Val Ala Ala Ile Ser Arg 325 330 <210> SEQ ID NO 6 <211> LENGTH: 330 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT5) <400> SEQUENCE: 6 Met Lys Pro Cys Met Thr Ala Leu Arg Gln Val Ile Gln Pro Leu Ser 1 5 10 15 Leu Asn Phe Gln Gly Asn Met Val Asp Val Pro Phe Phe Arg Arg Lys 20 25 30 Asp Lys Val Val Phe Val Met Gly Ala Thr Gly Thr Gly Lys Ser Arg 35 40 45 Leu Ala Ile Asp Leu Ala Thr Arg Phe Pro Ala Glu Ile Val Asn Ser 50 55 60 Asp Lys Ile Gln Val Tyr Lys Gly Leu Asp Ile Val Thr Asn Lys Val 65 70 75 80 Thr Pro Glu Glu Ser Leu Gly Val Pro His His Leu Leu Gly Thr Val 85 90 95 His Asp Thr Tyr Glu Asp Phe Thr Ala Glu Asp Phe Gln Arg Glu Ala 100 105 110 Ile Arg Ala Val Glu Ser Ile Val Gln Arg Asp Arg Val Pro Ile Ile 115 120 125 Ala Gly Gly Ser Asn Ser Tyr Ile Glu Ala Leu Val Asn Asp Cys Val 130 135 140 Asp Phe Arg Leu Arg Tyr Asn Cys Cys Phe Leu Trp Val Asp Val Ser 145 150 155 160 Arg Pro Val Leu His Ser Phe Val Ser Glu Arg Val Asp Lys Met Val 165 170 175 Asp Met Gly Leu Val Asp Glu Val Arg Arg Ile Phe Asp Pro Ser Ser 180 185 190 Ser Asp Tyr Ser Ala Gly Ile Arg Arg Ala Ile Gly Val Pro Glu Leu 195 200 205 Asp Glu Phe Leu Arg Ser Glu Met Arg Asn Tyr Pro Ala Glu Thr Thr 210 215 220 Glu Arg Leu Leu Glu Thr Ala Ile Glu Lys Ile Lys Glu Asn Thr Cys 225 230 235 240 Leu Leu Ala Cys Arg Gln Leu Gln Lys Ile Gln Arg Leu Tyr Lys Gln 245 250 255 Trp Lys Trp Asn Met His Arg Val Asp Ala Thr Glu Val Phe Leu Arg 260 265 270 Arg Gly Glu Glu Ala Asp Glu Ala Trp Asp Asn Ser Val Ala His Pro 275 280 285 Ser Ala Leu Ala Val Glu Lys Phe Leu Ser Tyr Ser Asp Asp His His 290 295 300 Leu Glu Gly Ala Asn Ile Leu Leu Pro Glu Ile Ser Ala Val Pro Pro 305 310 315 320 Leu Pro Ala Ala Val Ala Ala Ile Ser Arg 325 330 <210> SEQ ID NO 7 <211> LENGTH: 990 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT7) <400> SEQUENCE: 7 atg aag ttc tca atc tca tca ctg aag cag gta caa cca atc ttg tgc 48 Met Lys Phe Ser Ile Ser Ser Leu Lys Gln Val Gln Pro Ile Leu Cys 1 5 10 15 ttc aag aac aag cta tct aag gtc aac gtc aac tct ttt ctc cat ccc 96 Phe Lys Asn Lys Leu Ser Lys Val Asn Val Asn Ser Phe Leu His Pro 20 25 30 aaa gaa aaa gtc atc ttt gtg atg gga gct acc gga tcg ggt aag tct 144 Lys Glu Lys Val Ile Phe Val Met Gly Ala Thr Gly Ser Gly Lys Ser 35 40 45 cgt ctc gcc atc gac cta gca act cgt ttt caa gga gag atc ata aac 192 Arg Leu Ala Ile Asp Leu Ala Thr Arg Phe Gln Gly Glu Ile Ile Asn 50 55 60 tcc gac aag att caa ctt tac aag ggc cta gac gtc cta aca aac aaa 240 Ser Asp Lys Ile Gln Leu Tyr Lys Gly Leu Asp Val Leu Thr Asn Lys 65 70 75 80 gtc acc cct aaa gaa tgc cga ggc gtg cct cac cac ttg ctt gga gta 288 Val Thr Pro Lys Glu Cys Arg Gly Val Pro His His Leu Leu Gly Val 85 90 95 ttc gac tcc gaa gcc gga aac cta acg gcc acc cag tat agc cgc ctt 336 Phe Asp Ser Glu Ala Gly Asn Leu Thr Ala Thr Gln Tyr Ser Arg Leu 100 105 110 gcg tca caa gca atc tcg aaa ctc tca gcg aac aac aag ctt ccc ata 384 Ala Ser Gln Ala Ile Ser Lys Leu Ser Ala Asn Asn Lys Leu Pro Ile 115 120 125 gta gcc ggt gga tca aac tct tac atc gaa gca ctt gtt aat cat tcc 432 Val Ala Gly Gly Ser Asn Ser Tyr Ile Glu Ala Leu Val Asn His Ser 130 135 140 tcg ggg ttt tta tta aac aac tac gat tgt tgt ttc att tgg gtc gac 480 Ser Gly Phe Leu Leu Asn Asn Tyr Asp Cys Cys Phe Ile Trp Val Asp 145 150 155 160 gtt tcc tta ccc gta ctt aac tcc ttt gtc tca aaa cgt gtc gac cgc 528 Val Ser Leu Pro Val Leu Asn Ser Phe Val Ser Lys Arg Val Asp Arg 165 170 175 atg atg gaa gca gga tta ctc gaa gaa gta aga gaa gtg ttc aat cca 576 Met Met Glu Ala Gly Leu Leu Glu Glu Val Arg Glu Val Phe Asn Pro 180 185 190 aaa gcg aat tac tcc gta ggg ata cga cga gct atc gga gtc ccc gag 624 Lys Ala Asn Tyr Ser Val Gly Ile Arg Arg Ala Ile Gly Val Pro Glu 195 200 205 ctc cat gaa tat tta cgt aac gaa tct cta gtg gac cgt gcc aca aaa 672 Leu His Glu Tyr Leu Arg Asn Glu Ser Leu Val Asp Arg Ala Thr Lys 210 215 220 agt aaa atg ctt gac gta gcc gtt aaa aat atc aaa aag aac act gag 720 Ser Lys Met Leu Asp Val Ala Val Lys Asn Ile Lys Lys Asn Thr Glu 225 230 235 240 att tta gct tgt cga cag tta aaa aag att caa cgg ctt cac aag aag 768 Ile Leu Ala Cys Arg Gln Leu Lys Lys Ile Gln Arg Leu His Lys Lys 245 250 255 tgg aag atg tct atg cat cgt gtt gac gcc act gag gtg ttc ttg aaa 816 Trp Lys Met Ser Met His Arg Val Asp Ala Thr Glu Val Phe Leu Lys 260 265 270 cgc aac gta gaa gaa caa gac gag gct tgg gag aat ctt gta gcg aga 864 Arg Asn Val Glu Glu Gln Asp Glu Ala Trp Glu Asn Leu Val Ala Arg 275 280 285 cca agc gag aga atc gtc gat aag ttt tat aat aat aat aac caa ctg 912 Pro Ser Glu Arg Ile Val Asp Lys Phe Tyr Asn Asn Asn Asn Gln Leu 290 295 300 aaa aat gat gat gtt gag cac tgt ttg gcg gca tct tac ggc gga gga 960 Lys Asn Asp Asp Val Glu His Cys Leu Ala Ala Ser Tyr Gly Gly Gly 305 310 315 320 agt gga agt aga gcc cac aat atg ata tga 990 Ser Gly Ser Arg Ala His Asn Met Ile 325 <210> SEQ ID NO 8 <211> LENGTH: 329 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT7) <400> SEQUENCE: 8 Met Lys Phe Ser Ile Ser Ser Leu Lys Gln Val Gln Pro Ile Leu Cys 1 5 10 15 Phe Lys Asn Lys Leu Ser Lys Val Asn Val Asn Ser Phe Leu His Pro 20 25 30 Lys Glu Lys Val Ile Phe Val Met Gly Ala Thr Gly Ser Gly Lys Ser 35 40 45 Arg Leu Ala Ile Asp Leu Ala Thr Arg Phe Gln Gly Glu Ile Ile Asn 50 55 60 Ser Asp Lys Ile Gln Leu Tyr Lys Gly Leu Asp Val Leu Thr Asn Lys 65 70 75 80 Val Thr Pro Lys Glu Cys Arg Gly Val Pro His His Leu Leu Gly Val 85 90 95 Phe Asp Ser Glu Ala Gly Asn Leu Thr Ala Thr Gln Tyr Ser Arg Leu 100 105 110 Ala Ser Gln Ala Ile Ser Lys Leu Ser Ala Asn Asn Lys Leu Pro Ile 115 120 125 Val Ala Gly Gly Ser Asn Ser Tyr Ile Glu Ala Leu Val Asn His Ser 130 135 140 Ser Gly Phe Leu Leu Asn Asn Tyr Asp Cys Cys Phe Ile Trp Val Asp 145 150 155 160 Val Ser Leu Pro Val Leu Asn Ser Phe Val Ser Lys Arg Val Asp Arg 165 170 175 Met Met Glu Ala Gly Leu Leu Glu Glu Val Arg Glu Val Phe Asn Pro 180 185 190 Lys Ala Asn Tyr Ser Val Gly Ile Arg Arg Ala Ile Gly Val Pro Glu 195 200 205 Leu His Glu Tyr Leu Arg Asn Glu Ser Leu Val Asp Arg Ala Thr Lys 210 215 220 Ser Lys Met Leu Asp Val Ala Val Lys Asn Ile Lys Lys Asn Thr Glu 225 230 235 240 Ile Leu Ala Cys Arg Gln Leu Lys Lys Ile Gln Arg Leu His Lys Lys 245 250 255 Trp Lys Met Ser Met His Arg Val Asp Ala Thr Glu Val Phe Leu Lys 260 265 270 Arg Asn Val Glu Glu Gln Asp Glu Ala Trp Glu Asn Leu Val Ala Arg 275 280 285 Pro Ser Glu Arg Ile Val Asp Lys Phe Tyr Asn Asn Asn Asn Gln Leu 290 295 300 Lys Asn Asp Asp Val Glu His Cys Leu Ala Ala Ser Tyr Gly Gly Gly 305 310 315 320 Ser Gly Ser Arg Ala His Asn Met Ile 325 <210> SEQ ID NO 9 <211> LENGTH: 993 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT8) <400> SEQUENCE: 9 atg caa aat ctt acg tcc aca ttc gtc tct cct tcc atg atc ccg atc 48 Met Gln Asn Leu Thr Ser Thr Phe Val Ser Pro Ser Met Ile Pro Ile 1 5 10 15 act tct ccg cgg ctg cga ctg cca cca cca cga tca gta gtt ccc atg 96 Thr Ser Pro Arg Leu Arg Leu Pro Pro Pro Arg Ser Val Val Pro Met 20 25 30 act acc gtt tgc atg gaa caa tca tac aag caa aaa gtg gtt gtg atc 144 Thr Thr Val Cys Met Glu Gln Ser Tyr Lys Gln Lys Val Val Val Ile 35 40 45 atg gga gcc acc gga tca ggc aag tca tgc ctc tca atc gat cta gca 192 Met Gly Ala Thr Gly Ser Gly Lys Ser Cys Leu Ser Ile Asp Leu Ala 50 55 60 act cgt ttc tct ggc gag atc gtc aat tcc gac aag att caa ttc tac 240 Thr Arg Phe Ser Gly Glu Ile Val Asn Ser Asp Lys Ile Gln Phe Tyr 65 70 75 80 gat gga ttg aag gtc act acg aat caa atg agc atc ctt gag aga tgt 288 Asp Gly Leu Lys Val Thr Thr Asn Gln Met Ser Ile Leu Glu Arg Cys 85 90 95 gga gtc cct cac cat ctc ctt ggt gag ctc cct ccg gat gat agc gaa 336 Gly Val Pro His His Leu Leu Gly Glu Leu Pro Pro Asp Asp Ser Glu 100 105 110 cta act acc tcc gaa ttc cgc tct ttg gcg tcg cgg tcc atc tcc gag 384 Leu Thr Thr Ser Glu Phe Arg Ser Leu Ala Ser Arg Ser Ile Ser Glu 115 120 125 att act gct cgt gga aac ctc ccg att ata gct ggt gga tca aac tcc 432 Ile Thr Ala Arg Gly Asn Leu Pro Ile Ile Ala Gly Gly Ser Asn Ser 130 135 140 ttc att cat gct ctc ctt gtc gac cgt ttt gac ccc aaa acc tat cca 480 Phe Ile His Ala Leu Leu Val Asp Arg Phe Asp Pro Lys Thr Tyr Pro 145 150 155 160 ttc tct tct gag aca tcc atc tct tcc ggc ttg agg tac gag tgt tgc 528 Phe Ser Ser Glu Thr Ser Ile Ser Ser Gly Leu Arg Tyr Glu Cys Cys 165 170 175 ttc ctt tgg gtg gat gtc tca gtg tcg gtc ctg ttc gag tac ctc tcg 576 Phe Leu Trp Val Asp Val Ser Val Ser Val Leu Phe Glu Tyr Leu Ser 180 185 190 aaa cgt gtc gac cag atg atg gag tca ggg atg ttc gag gag cta gcc 624 Lys Arg Val Asp Gln Met Met Glu Ser Gly Met Phe Glu Glu Leu Ala 195 200 205 ggt ttc tac gac ccg aga tat tcc ggg tcc gca atc cga gcc cac ggg 672 Gly Phe Tyr Asp Pro Arg Tyr Ser Gly Ser Ala Ile Arg Ala His Gly 210 215 220 att cac aag acc ata gga ata ccc gag ttc gac cgg tac ttc agc tta 720 Ile His Lys Thr Ile Gly Ile Pro Glu Phe Asp Arg Tyr Phe Ser Leu 225 230 235 240 tac ccg cct gag aga aag cag aag atg tcc gaa tgg gac caa gca aga 768 Tyr Pro Pro Glu Arg Lys Gln Lys Met Ser Glu Trp Asp Gln Ala Arg 245 250 255 aag ggg gcg tat gac gaa gct gtc caa gag atc aaa gag aac aca tgg 816 Lys Gly Ala Tyr Asp Glu Ala Val Gln Glu Ile Lys Glu Asn Thr Trp 260 265 270 agg ctt gcg aag aag cag att gag agg atc atg aag ctg aaa agc agc 864 Arg Leu Ala Lys Lys Gln Ile Glu Arg Ile Met Lys Leu Lys Ser Ser 275 280 285 gga tgg gac att cag agg ttg gac gct acg ccg tca ttt gga aga tcg 912 Gly Trp Asp Ile Gln Arg Leu Asp Ala Thr Pro Ser Phe Gly Arg Ser 290 295 300 tca aga gag att tgg gac aat act gtt ttg gat gaa agc atc aag gtt 960 Ser Arg Glu Ile Trp Asp Asn Thr Val Leu Asp Glu Ser Ile Lys Val 305 310 315 320 gtg aaa cgc ttc ttg gtg aaa gac aaa gtg tga 993 Val Lys Arg Phe Leu Val Lys Asp Lys Val 325 330 <210> SEQ ID NO 10 <211> LENGTH: 330 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT8) <400> SEQUENCE: 10 Met Gln Asn Leu Thr Ser Thr Phe Val Ser Pro Ser Met Ile Pro Ile 1 5 10 15 Thr Ser Pro Arg Leu Arg Leu Pro Pro Pro Arg Ser Val Val Pro Met 20 25 30 Thr Thr Val Cys Met Glu Gln Ser Tyr Lys Gln Lys Val Val Val Ile 35 40 45 Met Gly Ala Thr Gly Ser Gly Lys Ser Cys Leu Ser Ile Asp Leu Ala 50 55 60 Thr Arg Phe Ser Gly Glu Ile Val Asn Ser Asp Lys Ile Gln Phe Tyr 65 70 75 80 Asp Gly Leu Lys Val Thr Thr Asn Gln Met Ser Ile Leu Glu Arg Cys 85 90 95 Gly Val Pro His His Leu Leu Gly Glu Leu Pro Pro Asp Asp Ser Glu 100 105 110 Leu Thr Thr Ser Glu Phe Arg Ser Leu Ala Ser Arg Ser Ile Ser Glu 115 120 125 Ile Thr Ala Arg Gly Asn Leu Pro Ile Ile Ala Gly Gly Ser Asn Ser 130 135 140 Phe Ile His Ala Leu Leu Val Asp Arg Phe Asp Pro Lys Thr Tyr Pro 145 150 155 160 Phe Ser Ser Glu Thr Ser Ile Ser Ser Gly Leu Arg Tyr Glu Cys Cys 165 170 175 Phe Leu Trp Val Asp Val Ser Val Ser Val Leu Phe Glu Tyr Leu Ser 180 185 190 Lys Arg Val Asp Gln Met Met Glu Ser Gly Met Phe Glu Glu Leu Ala 195 200 205 Gly Phe Tyr Asp Pro Arg Tyr Ser Gly Ser Ala Ile Arg Ala His Gly 210 215 220 Ile His Lys Thr Ile Gly Ile Pro Glu Phe Asp Arg Tyr Phe Ser Leu 225 230 235 240 Tyr Pro Pro Glu Arg Lys Gln Lys Met Ser Glu Trp Asp Gln Ala Arg 245 250 255 Lys Gly Ala Tyr Asp Glu Ala Val Gln Glu Ile Lys Glu Asn Thr Trp 260 265 270 Arg Leu Ala Lys Lys Gln Ile Glu Arg Ile Met Lys Leu Lys Ser Ser 275 280 285 Gly Trp Asp Ile Gln Arg Leu Asp Ala Thr Pro Ser Phe Gly Arg Ser 290 295 300 Ser Arg Glu Ile Trp Asp Asn Thr Val Leu Asp Glu Ser Ile Lys Val 305 310 315 320 Val Lys Arg Phe Leu Val Lys Asp Lys Val 325 330 <210> SEQ ID NO 11 <211> LENGTH: 1071 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT1) <400> SEQUENCE: 11 atg aca gaa ctc aac ttc cac ctc ctc cca ata atc tcc gat cgc ttc 48 Met Thr Glu Leu Asn Phe His Leu Leu Pro Ile Ile Ser Asp Arg Phe 1 5 10 15 acg acg acg acg aca aca tca ccg tcg ttc tcg tca cat tct tct tct 96 Thr Thr Thr Thr Thr Thr Ser Pro Ser Phe Ser Ser His Ser Ser Ser 20 25 30 tct tct tct ctt ctc tct ttc acc aaa cga aga cga aaa cac caa cct 144 Ser Ser Ser Leu Leu Ser Phe Thr Lys Arg Arg Arg Lys His Gln Pro 35 40 45 tta gta tca tcc ata cgc atg gaa cag tca cgg tca cgg aat cgg aaa 192 Leu Val Ser Ser Ile Arg Met Glu Gln Ser Arg Ser Arg Asn Arg Lys 50 55 60 gac aaa gtc gtc gtc att tta gga gca acc ggc gcc gga aaa tca aga 240 Asp Lys Val Val Val Ile Leu Gly Ala Thr Gly Ala Gly Lys Ser Arg 65 70 75 80 ctt tcc gtc gat ctc gct act cgt ttc cct tca gag atc ata aac tcc 288 Leu Ser Val Asp Leu Ala Thr Arg Phe Pro Ser Glu Ile Ile Asn Ser 85 90 95 gat aaa atc caa gtc tac gaa gga tta gag atc aca acg aat cag att 336 Asp Lys Ile Gln Val Tyr Glu Gly Leu Glu Ile Thr Thr Asn Gln Ile 100 105 110 acg tta caa gac cgt cgc ggc gtt cct cac cat ctc ctc ggc gtc atc 384 Thr Leu Gln Asp Arg Arg Gly Val Pro His His Leu Leu Gly Val Ile 115 120 125 aac ccc gaa cac ggc gaa cta acc gcc gga gag ttt cgc tcc gcc gct 432 Asn Pro Glu His Gly Glu Leu Thr Ala Gly Glu Phe Arg Ser Ala Ala 130 135 140 tca aac gtc gtc aaa gag ata act tct cgt caa aag gtt ccg att atc 480 Ser Asn Val Val Lys Glu Ile Thr Ser Arg Gln Lys Val Pro Ile Ile 145 150 155 160 gcc ggt gga tct aac tct ttc gtc cac gca ctc tta gct caa cga ttc 528 Ala Gly Gly Ser Asn Ser Phe Val His Ala Leu Leu Ala Gln Arg Phe 165 170 175 gac cca aag ttc gat cct ttt tca tcc ggg tcg tgt tta atc agc tcc 576 Asp Pro Lys Phe Asp Pro Phe Ser Ser Gly Ser Cys Leu Ile Ser Ser 180 185 190 gat ttg cgt tac gag tgt tgt ttc atc tgg gtc gat gta tcg gag act 624 Asp Leu Arg Tyr Glu Cys Cys Phe Ile Trp Val Asp Val Ser Glu Thr 195 200 205 gtt ctc tac gag tat ctt ctc aga aga gtc gac gaa atg atg gat tca 672 Val Leu Tyr Glu Tyr Leu Leu Arg Arg Val Asp Glu Met Met Asp Ser 210 215 220 ggt atg ttc gaa gag ctg tct aga ttc tac gac ccg gtt aaa tcc ggt 720 Gly Met Phe Glu Glu Leu Ser Arg Phe Tyr Asp Pro Val Lys Ser Gly 225 230 235 240 tta gaa acc cgg ttt ggg att agg aaa gct ata ggt gta ccg gag ttt 768 Leu Glu Thr Arg Phe Gly Ile Arg Lys Ala Ile Gly Val Pro Glu Phe 245 250 255 gac ggt tac ttc aaa gag tat cca ccg gag aag aag atg ata aag tgg 816 Asp Gly Tyr Phe Lys Glu Tyr Pro Pro Glu Lys Lys Met Ile Lys Trp 260 265 270 gac gct tta aga aaa gcg gcg tac gat aag gcg gtt gat gat atc aaa 864 Asp Ala Leu Arg Lys Ala Ala Tyr Asp Lys Ala Val Asp Asp Ile Lys 275 280 285 agg aac acg tgg acg tta gcg aag aga caa gtg aag aag att gag atg 912 Arg Asn Thr Trp Thr Leu Ala Lys Arg Gln Val Lys Lys Ile Glu Met 290 295 300 cta aaa gac gct ggt tgg gaa ata gaa aga gtt gat gca acg gcg tcg 960 Leu Lys Asp Ala Gly Trp Glu Ile Glu Arg Val Asp Ala Thr Ala Ser 305 310 315 320 ttt aaa gca gtg atg atg aag agt tcg tcg gag aag aag tgg aga gag 1008 Phe Lys Ala Val Met Met Lys Ser Ser Ser Glu Lys Lys Trp Arg Glu 325 330 335 aat tgg gaa gag caa gtg ttg gag cca agc gta aag att gtg aag cgg 1056 Asn Trp Glu Glu Gln Val Leu Glu Pro Ser Val Lys Ile Val Lys Arg 340 345 350 cat ttg gtg caa aat 1071 His Leu Val Gln Asn 355 <210> SEQ ID NO 12 <211> LENGTH: 357 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT1) <400> SEQUENCE: 12 Met Thr Glu Leu Asn Phe His Leu Leu Pro Ile Ile Ser Asp Arg Phe 1 5 10 15 Thr Thr Thr Thr Thr Thr Ser Pro Ser Phe Ser Ser His Ser Ser Ser 20 25 30 Ser Ser Ser Leu Leu Ser Phe Thr Lys Arg Arg Arg Lys His Gln Pro 35 40 45 Leu Val Ser Ser Ile Arg Met Glu Gln Ser Arg Ser Arg Asn Arg Lys 50 55 60 Asp Lys Val Val Val Ile Leu Gly Ala Thr Gly Ala Gly Lys Ser Arg 65 70 75 80 Leu Ser Val Asp Leu Ala Thr Arg Phe Pro Ser Glu Ile Ile Asn Ser 85 90 95 Asp Lys Ile Gln Val Tyr Glu Gly Leu Glu Ile Thr Thr Asn Gln Ile 100 105 110 Thr Leu Gln Asp Arg Arg Gly Val Pro His His Leu Leu Gly Val Ile 115 120 125 Asn Pro Glu His Gly Glu Leu Thr Ala Gly Glu Phe Arg Ser Ala Ala 130 135 140 Ser Asn Val Val Lys Glu Ile Thr Ser Arg Gln Lys Val Pro Ile Ile 145 150 155 160 Ala Gly Gly Ser Asn Ser Phe Val His Ala Leu Leu Ala Gln Arg Phe 165 170 175 Asp Pro Lys Phe Asp Pro Phe Ser Ser Gly Ser Cys Leu Ile Ser Ser 180 185 190 Asp Leu Arg Tyr Glu Cys Cys Phe Ile Trp Val Asp Val Ser Glu Thr 195 200 205 Val Leu Tyr Glu Tyr Leu Leu Arg Arg Val Asp Glu Met Met Asp Ser 210 215 220 Gly Met Phe Glu Glu Leu Ser Arg Phe Tyr Asp Pro Val Lys Ser Gly 225 230 235 240 Leu Glu Thr Arg Phe Gly Ile Arg Lys Ala Ile Gly Val Pro Glu Phe 245 250 255 Asp Gly Tyr Phe Lys Glu Tyr Pro Pro Glu Lys Lys Met Ile Lys Trp 260 265 270 Asp Ala Leu Arg Lys Ala Ala Tyr Asp Lys Ala Val Asp Asp Ile Lys 275 280 285 Arg Asn Thr Trp Thr Leu Ala Lys Arg Gln Val Lys Lys Ile Glu Met 290 295 300 Leu Lys Asp Ala Gly Trp Glu Ile Glu Arg Val Asp Ala Thr Ala Ser 305 310 315 320 Phe Lys Ala Val Met Met Lys Ser Ser Ser Glu Lys Lys Trp Arg Glu 325 330 335 Asn Trp Glu Glu Gln Val Leu Glu Pro Ser Val Lys Ile Val Lys Arg 340 345 350 His Leu Val Gln Asn 355 <210> SEQ ID NO 13 <211> LENGTH: 1029 <212> TYPE: DNA <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Nucleotide sequence of DNA encoding cytokinin synthase-like protein (AtIPT6) <400> SEQUENCE: 13 atg caa caa ctc atg acc ttg tta tca cca cca ctc tct cat tct tct 48 Met Gln Gln Leu Met Thr Leu Leu Ser Pro Pro Leu Ser His Ser Ser 1 5 10 15 ctc ctt ccc acc gtc act acc aaa ttc ggg tca cca cga tta gtc act 96 Leu Leu Pro Thr Val Thr Thr Lys Phe Gly Ser Pro Arg Leu Val Thr 20 25 30 acg tgc atg ggc cat gca ggg cgt aaa aat atc aag gat aag gtg gtt 144 Thr Cys Met Gly His Ala Gly Arg Lys Asn Ile Lys Asp Lys Val Val 35 40 45 ctc atc aca ggt aca aca ggc aca ggc aag tca cgc ctc tca gtc gat 192 Leu Ile Thr Gly Thr Thr Gly Thr Gly Lys Ser Arg Leu Ser Val Asp 50 55 60 ctt gcc acc cgt ttt ttt ccc gcc gag atc ata aac tcg gac aaa atg 240 Leu Ala Thr Arg Phe Phe Pro Ala Glu Ile Ile Asn Ser Asp Lys Met 65 70 75 80 caa atc tac aag gga ttc gag att gtc aca aat cta atc cca ctg cat 288 Gln Ile Tyr Lys Gly Phe Glu Ile Val Thr Asn Leu Ile Pro Leu His 85 90 95 gag caa gga gga gtc ccg cac cat ctt cta ggt cag ttc cac cca caa 336 Glu Gln Gly Gly Val Pro His His Leu Leu Gly Gln Phe His Pro Gln 100 105 110 gac ggt gaa ctc acc cct gca gag ttc cgt tct ttg gcg aca ctg tcc 384 Asp Gly Glu Leu Thr Pro Ala Glu Phe Arg Ser Leu Ala Thr Leu Ser 115 120 125 atc tct aaa cta att tct agc aag aaa ctc ccg att gta gtt ggt gga 432 Ile Ser Lys Leu Ile Ser Ser Lys Lys Leu Pro Ile Val Val Gly Gly 130 135 140 tcc aac tcc ttc aat cac gct cta ctc gcc gag cgt ttt gac ccg gat 480 Ser Asn Ser Phe Asn His Ala Leu Leu Ala Glu Arg Phe Asp Pro Asp 145 150 155 160 att gat cca ttc tct ccc gga tcg agt ctt tca acg atc tgc tct gac 528 Ile Asp Pro Phe Ser Pro Gly Ser Ser Leu Ser Thr Ile Cys Ser Asp 165 170 175 cta agg tac aaa tgt tgc atc tta tgg gtt gat gtt tta gag ccg gtt 576 Leu Arg Tyr Lys Cys Cys Ile Leu Trp Val Asp Val Leu Glu Pro Val 180 185 190 ctg ttc caa cac ttg tgc aat cgt gtc gac caa atg atc gag tcg gga 624 Leu Phe Gln His Leu Cys Asn Arg Val Asp Gln Met Ile Glu Ser Gly 195 200 205 ttg gtc gag cag ctt gcc gaa ttg tac gac cct gtt gta gat tcg ggt 672 Leu Val Glu Gln Leu Ala Glu Leu Tyr Asp Pro Val Val Asp Ser Gly 210 215 220 cga cga cta ggg gtt cgg aag acg ata gga gta gag gag ttc gac cga 720 Arg Arg Leu Gly Val Arg Lys Thr Ile Gly Val Glu Glu Phe Asp Arg 225 230 235 240 tac ttt aga gta tac cct aag gag atg gac aag gga att tgg gac tta 768 Tyr Phe Arg Val Tyr Pro Lys Glu Met Asp Lys Gly Ile Trp Asp Leu 245 250 255 gcg aga aag gcg gcg tac gag gag aca gtg aag ggg atg aaa gag agg 816 Ala Arg Lys Ala Ala Tyr Glu Glu Thr Val Lys Gly Met Lys Glu Arg 260 265 270 aca tgt cgg ttg gtg aag aag cag aaa gag aag atc atg aag ctg ata 864 Thr Cys Arg Leu Val Lys Lys Gln Lys Glu Lys Ile Met Lys Leu Ile 275 280 285 aga ggt ggt tgg gag att aag agg ctt gac gct acg gcg gca att atg 912 Arg Gly Gly Trp Glu Ile Lys Arg Leu Asp Ala Thr Ala Ala Ile Met 290 295 300 gct gag ctg aat caa agt acg gca aag gga gaa gga aag aat ggg aga 960 Ala Glu Leu Asn Gln Ser Thr Ala Lys Gly Glu Gly Lys Asn Gly Arg 305 310 315 320 gag att tgg gaa aaa cac att gtg gat gaa agt gtc gag att gtc aag 1008 Glu Ile Trp Glu Lys His Ile Val Asp Glu Ser Val Glu Ile Val Lys 325 330 335 aag ttt ttg ttg gaa gtt tag 1029 Lys Phe Leu Leu Glu Val 340 <210> SEQ ID NO 14 <211> LENGTH: 342 <212> TYPE: PRT <213> ORGANISM: Arabidopsis thaliana <223> OTHER INFORMATION: Amino acid sequence of cytokinin synthase-like protein (AtIPT6) <400> SEQUENCE: 14 Met Gln Gln Leu Met Thr Leu Leu Ser Pro Pro Leu Ser His Ser Ser 1 5 10 15 Leu Leu Pro Thr Val Thr Thr Lys Phe Gly Ser Pro Arg Leu Val Thr 20 25 30 Thr Cys Met Gly His Ala Gly Arg Lys Asn Ile Lys Asp Lys Val Val 35 40 45 Leu Ile Thr Gly Thr Thr Gly Thr Gly Lys Ser Arg Leu Ser Val Asp 50 55 60 Leu Ala Thr Arg Phe Phe Pro Ala Glu Ile Ile Asn Ser Asp Lys Met 65 70 75 80 Gln Ile Tyr Lys Gly Phe Glu Ile Val Thr Asn Leu Ile Pro Leu His 85 90 95 Glu Gln Gly Gly Val Pro His His Leu Leu Gly Gln Phe His Pro Gln 100 105 110 Asp Gly Glu Leu Thr Pro Ala Glu Phe Arg Ser Leu Ala Thr Leu Ser 115 120 125 Ile Ser Lys Leu Ile Ser Ser Lys Lys Leu Pro Ile Val Val Gly Gly 130 135 140 Ser Asn Ser Phe Asn His Ala Leu Leu Ala Glu Arg Phe Asp Pro Asp 145 150 155 160 Ile Asp Pro Phe Ser Pro Gly Ser Ser Leu Ser Thr Ile Cys Ser Asp 165 170 175 Leu Arg Tyr Lys Cys Cys Ile Leu Trp Val Asp Val Leu Glu Pro Val 180 185 190 Leu Phe Gln His Leu Cys Asn Arg Val Asp Gln Met Ile Glu Ser Gly 195 200 205 Leu Val Glu Gln Leu Ala Glu Leu Tyr Asp Pro Val Val Asp Ser Gly 210 215 220 Arg Arg Leu Gly Val Arg Lys Thr Ile Gly Val Glu Glu Phe Asp Arg 225 230 235 240 Tyr Phe Arg Val Tyr Pro Lys Glu Met Asp Lys Gly Ile Trp Asp Leu 245 250 255 Ala Arg Lys Ala Ala Tyr Glu Glu Thr Val Lys Gly Met Lys Glu Arg 260 265 270 Thr Cys Arg Leu Val Lys Lys Gln Lys Glu Lys Ile Met Lys Leu Ile 275 280 285 Arg Gly Gly Trp Glu Ile Lys Arg Leu Asp Ala Thr Ala Ala Ile Met 290 295 300 Ala Glu Leu Asn Gln Ser Thr Ala Lys Gly Glu Gly Lys Asn Gly Arg 305 310 315 320 Glu Ile Trp Glu Lys His Ile Val Asp Glu Ser Val Glu Ile Val Lys 325 330 335 Lys Phe Leu Leu Glu Val 340 <210> SEQ ID NO 15 <211> LENGTH: 32 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 398 <400> SEQUENCE: 15 tcccccgggc gatgatgatg ttaaacccta gc 32 <210> SEQ ID NO 16 <211> LENGTH: 36 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 399 <400> SEQUENCE: 16 tcccccgggt caatttactt ctgcttcttg aacttc 36 <210> SEQ ID NO 17 <211> LENGTH: 30 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 421 <400> SEQUENCE: 17 aaaatgaagt gtaatgacaa aatggttgtg 30 <210> SEQ ID NO 18 <211> LENGTH: 27 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 407 <400> SEQUENCE: 18 gtccaaacta gttaagactt aaaaatc 27 <210> SEQ ID NO 19 <211> LENGTH: 27 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 703 <400> SEQUENCE: 19 caccagcaag tttatattgc aaagcgt 27 <210> SEQ ID NO 20 <211> LENGTH: 27 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 705 <400> SEQUENCE: 20 gttgtaacca cgtaaaagat aagggtg 27 <210> SEQ ID NO 21 <211> LENGTH: 35 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 480 <400> SEQUENCE: 21 ggaattccat atgaagtgta atgacaaaat ggttg 35 <210> SEQ ID NO 22 <211> LENGTH: 35 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 481 <400> SEQUENCE: 22 gaagatctgt ccaaactagt taagacttaa aaatc 35 <210> SEQ ID NO 23 <211> LENGTH: 33 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 550 <400> SEQUENCE: 23 gatccccggc atatgatgat gttaaaccct agc 33 <210> SEQ ID NO 24 <211> LENGTH: 38 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 551 <400> SEQUENCE: 24 acggtaccca tatgtcaatt tacttctgct tcttgaac 38 <210> SEQ ID NO 25 <211> LENGTH: 34 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 741 <400> SEQUENCE: 25 ttatacatat gaagccatgc atgacggctc taag 34 <210> SEQ ID NO 26 <211> LENGTH: 28 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 742 <400> SEQUENCE: 26 cgggatcctc accgggaaat cgccgcca 28 <210> SEQ ID NO 27 <211> LENGTH: 46 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 852 <400> SEQUENCE: 27 ctcgagttgg cgcgccaccc gggattaatt aagactagtg gggtac 46 <210> SEQ ID NO 28 <211> LENGTH: 42 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 853 <400> SEQUENCE: 28 cccactagtc ttaattaatc ccgggtggcg cgccaactcg ag 42 <210> SEQ ID NO 29 <211> LENGTH: 23 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 918 <400> SEQUENCE: 29 atgacagaac tcaacttcca cct 23 <210> SEQ ID NO 30 <211> LENGTH: 36 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 879 <400> SEQUENCE: 30 caaaaaaaag atctaatttt gcaccaaatg ccgctt 36 <210> SEQ ID NO 31 <211> LENGTH: 30 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 533 <400> SEQUENCE: 31 attatgcaaa atcttacgtc cacattcgtc 30 <210> SEQ ID NO 32 <211> LENGTH: 31 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 881 <400> SEQUENCE: 32 acaggatcct cacactttgt ctttcaccaa g 31 <210> SEQ ID NO 33 <211> LENGTH: 31 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 856 <400> SEQUENCE: 33 ccgctcgaga tgaagccatg catgacggct c 31 <210> SEQ ID NO 34 <211> LENGTH: 27 <212> TYPE: DNA <213> ORGANISM: Artificial Sequence <220> FEATURE: <221> NAME/KEY: <222> LOCATION: <223> OTHER INFORMATION: Primer 857 <400> SEQUENCE: 34 ggactagtca ccgggaaatc gccgcca 27 

1. A gene encoding a protein having cytokinin synthesis activity and an amino acid sequence described in SEQ ID NO. 2, 4, 6, 8, 10, 12 or
 14. 2. A gene encoding a protein having cytokinin synthesis activity and which has a modified amino acid sequence resulting from the addition and/or deletion of one or a plurality of amino acids and/or substitution by other amino acids in SEQ ID NO. 2, 4, 6, 8, 10, 12 or
 14. 3. A gene encoding a protein having cytokinin synthesis activity and which hybridizes with a nucleic acid or portion thereof having a nucleotide sequence described in SEQ ID NO. 1, 3, 5, 7, 9, 11 or 13 under stringent conditions.
 4. A protein encoded by a gene according to any of claims 1 through
 3. 5. A vector comprising a gene according to any of claims 1 through
 3. 6. A host transformed by a vector according to claim
 5. 7. A host according to claim 6, wherein the transformed host is a plant or plant cells.
 8. A production method of cytokinin synthase comprising: culturing or growing the host according to claim 6 or 7, and harvesting the cytokinin synthase from said host.
 9. A plant or plant cells into which the gene according to any of claims 1 through 3 has been inserted.
 10. A method for regulating the growth of a plant or plant cells by inserting a gene according to any of claims 1 through 3 into a plant or plant cells and expressing said gene.
 11. A method for inducing adventitious bud formation by a plant or plant cells by inserting a gene according to any of claims 1 through 3 into a plant or plant cells, and expressing said gene.
 12. A method for searching for a plant gene that encodes an isopentenyl group transferase based on homology with the amino acid sequence GxTxxGK[ST]xxxxx[VLI]xxxxxxx[VLI][VLI]xxDxxQx[57,60][VLI] [VLI]xGG[ST] (where, x indicates an arbitrary amino acid residue, amino acid residues enclosed in brackets [ ] indicate which one of the amino acid residues contained therein, and [a,b] indicates the number of arbitrary types of amino acid residues greater than or equal to a but less than or equal to b).
 13. A method according to claim 12, wherein the plant gene that encodes an isopentenyl group transferase is a gene originating in Arabidopsis thaliana.
 14. A method according to claim 12 or claim 13, wherein the plant gene that encodes an isopentenyl group transferase is a gene that encodes cytokinin synthase. 